Imaging device, inspection apparatus, and method of manufacturing electronic device

ABSTRACT

The imaging device includes a sensor substrate, a light-blocking substrate, a light-collecting substrate, a sealing material, and a light-transmitting member. The light-transmitting member includes a light-transmitting base disposed to be in contact with either the sensor substrate or the light-blocking substrate, and a light-transmitting resin which is filled between the base and the sensor substrate or the light-blocking substrate. A void is formed in at least a part of a space between the sealing material and the light-transmitting member.

This application is a divisional application of U.S. patent applicationSer. No. 13/971,044 filed Aug. 20, 2013, which claims priority toJapanese Patent Application No. 2012-191445 filed Aug. 31, 2012, theentire disclosures of which are herein incorporated by reference.

BACKGROUND

1. Technical Field

Several aspects of the present invention relates to an imaging device,an inspection apparatus loaded with the imaging device, and a method ofmanufacturing an electronic device.

2. Related Art

In order to improve portability and convenience of an electronic devicesuch as a biometric authentication device or a digital camera, it isimportant to make an image sensor (imaging device) compact whichcaptures a target object. For example, as described in JP-A-5-100186,there has been known an imaging device which becomes compact byinterposing a pinhole (light transmitting region) between a micro-lensand a light sensing element, and arranging the micro-lens, the lightsensing element, and the pinhole in a multiple way to correspond one toone each other.

In the imaging device in JP-A-5-100186, the light sensing element isdisposed on an optical axis that connects the pinhole and themicro-lens, and thereby light of an inspection object (inspection light)which is collected using the micro-lens and travels along the opticalaxis is caused to be incident on the light sensing element.

In the imaging device, if a light blocking substrate formed with thepinhole is disposed to be inclined with respect to a sensor substrateformed with the light sensing element, the light sensing element is notdisposed on the optical axis which connects the pinhole and themicro-lens, and light other than the inspection light is caused to beincident on the light sensing element. In order to inhibit such aproblem, it is necessary to dispose the light blocking substrate and thesensor substrate to be opposite to each other at a uniform gap.

If the light blocking substrate is disposed to be close to the sensorsubstrate, for example, if the pin hole is formed right on the lightsensing element, other than inspection light traveling along the opticalaxis, light other than the inspection light, which obliquely travelswith respect to the optical axis, is also incident on the light sensingelement. On the other hand, if the light blocking substrate and thesensor substrate are spaced apart from each other at an appropriate gap,light (inspection light) in the optical axis direction, which passesthrough the pinhole, is incident on the light sensing element, but light(light other than the inspection light) in an oblique direction withrespect to the optical axis, which passes through the pinhole, is notincident on the light sensing element. Specifically, on an optical pathof light (the above-mentioned light in an oblique direction with respectto the optical axis) other than the inspection light traveling to thelight sensing element, a light blocking film formed on the lightblocking substrate is present and light other than the inspection lightis blocked by the light blocking film, and thereby the light other thanthe inspection light is inhibited from being incident on the lightsensing element. Accordingly, in order to cause the inspection light tobe selectively incident on the light sensing element, it is necessary tospace (dispose) the light blocking substrate and the sensor substrateapart from each other at an appropriate gap. Specifically, if the gapbetween the light blocking substrate and the sensor substrate is set toan array pitch (approximately 50 μm to 100 μm) or more where the lightsensing element is arranged, the inspection light is caused to beselectively incident on the light sensing element.

As described above, in the imaging device in JP-A-5-100186, if the lightblocking substrate and the sensor substrate are disposed at a uniformgap of approximately 50 μm or more, light other than the inspectionlight which is a detection noise is not incident on the light sensingelement, and it is possible to detect detection light with a highaccuracy.

SUMMARY

However, for example, disposition of a pair of substrates at a uniformgap of several μm can be easily performed using a known technology suchas a liquid crystal display device and the like. However, there is aproblem that it is difficult to uniformly dispose the pair of substratesat a large gap of approximately 50 μm or more.

Specifically, by using the known technology, when a sealing materialincluding a gap material of approximately 50 μm or more is formed at aperipheral portion to dispose the pair of substrates to be opposite toeach other at a gap of approximately 50 μm, a region apart from asealing material whose inner side is hollow (air layer) is easilydeformed, and it is difficult to form a uniform gap throughout thesubstrate. Furthermore, there is also a problem that an interfacialreflection occurs at a boundary between the substrate and the air layerto attenuate the inspection light. Therefore, it is necessary to fillthe inner side of the sealing material with a filler. For example, in amethod where the inner side of the sealing material is filled with resinmaterial to cure the resin material, a volume change (curing shrinkage)occurs when curing the resin material. In a large gap of approximately50 μM or more, the content of the resin material filled in the gap islarge, and the curing shrinkage of the resin material also increases.Therefore, there are problems that influence (warp of the substrate) ofthe curing shrinkage of the resin material increases and it is difficultto dispose the light blocking substrate and the sensor substrate to beopposite to each other using a uniform gap. Furthermore, if any one ofthe light blocking substrate and the sensor substrate is pressed againstthe other substrate by interposing the resin material between the lightblocking substrate and the sensor substrate, there is a problem that theresin material filling the inside protrudes to the outside of a regionsurrounded by a sealing material to contaminate a terminal and the likeformed at the outside of the sealing material.

As described above, there is a problem that it is difficult to uniformlydispose the light blocking substrate and the sensor substrate at a largeinterval of approximately 50 μm or more.

The invention can be realized in the following embodiments orapplication examples.

Application Example 1

According to this application example, there is provided an imagingdevice, including a sensor substrate which has a sensing region where aphoto-electric conversion element is disposed, a light-blockingsubstrate which is disposed to be opposite to a surface of a side wherea sensing region of the sensor substrate is formed and a light blockingfilm is formed which has an opening portion at a position correspondingto a photo-electric conversion element, a light-collecting substratewhich is disposed so as to interpose a light-blocking substrate in aspace between the light-collecting substrate and the sensor substrateand has a micro-lens at a position corresponding to the photo-electricconversion element, a sealing material which includes a gap materialforming a predetermined gap between the sensor substrate formed aroundthe sensing region and the light-blocking substrate, and alight-transmitting member which covers the sensing region inside thesealing material and fills a space between the sensor substrate and thelight-blocking substrate. The light-transmitting member includes alight-transmitting base disposed to be in contact with either the sensorsubstrate or the light-blocking substrate, and a light-transmittingresin which is filled in a space between the base and the sensorsubstrate or the light-blocking substrate. A void is formed in at leasta part of space between the sealing material and the light-transmittingmember.

Between the light-blocking substrate and the sensor substrate, byforming a sealing material including a gap material forming apredetermined gap around a sensing region, it is possible to form apredetermined gap on the light-blocking substrate and the sensorsubstrate at the periphery of the sensing region. In addition, in thesensing region surrounded using the sealing material, alight-transmitting member configured to have a light-transmitting baseand a light-transmitting resin is filled. A void is formed between thesealing material and the light-transmitting member. The void is a spacefor storing an extra light-transmitting member, so that it is possibleto inhibit the extra light-transmitting member from protruding outside aregion surrounded using the sealing material. Additionally, thelight-transmitting member has two-layer configuration of the base andthe light-transmitting resin, so that it is possible to decrease thevolume of the light-transmitting resin in the light-transmitting membercompared to when the light-transmitting member is formed only using thelight-transmitting resin. Accordingly, an influence of a volume change(curing shrinkage) occurring in a process forming (curing) thelight-transmitting resin may be decreased. Furthermore, by processingthe base to have a uniform height (thickness), it is possible to form alight-transmitting member having a uniform thickness. Accordingly, evenin the sensing region, by the light-transmitting member having a uniformthickness, it is possible to uniformly dispose the light-blockingsubstrate and the sensor substrate using a predetermined gap.

Application Example 2

According to this application example, there is provided an imagingdevice, including a sensor substrate which has a sensing region where aphoto-electric conversion element is disposed, a light-blockingsubstrate which is disposed to be opposite to a surface of a side wherea sensing region of the sensor substrate is formed and a light blockingfilm is formed which has an opening portion at a position correspondingto a photo-electric conversion element, a light-collecting substratewhich is disposed so as to interpose a light-blocking substrate in aspace between the light-collecting substrate and the sensor substrateand has a micro-lens at a position corresponding to the photo-electricconversion element, and a light-transmitting member which covers thesensing region at the inside the sealing material and fills a spacebetween the sensor substrate and the light-blocking substrate to form apredetermined gap between the sensor substrate and the light blockingsubstrate. The light-transmitting member includes a light-transmittingbase disposed to be in contact with either the sensor substrate or thelight-blocking substrate, and a light-transmitting resin which is filledin a space between the base and the sensor substrate or thelight-blocking substrate.

Between the light-blocking substrate and the sensor substrate, thelight-transmitting member configured to have the light-transmitting baseand the light-transmitting resin covers and fills the sensing region.The light transmitting member is configured to have two layers of thebase and the light transmitting resin, and the initial base is processedto have a uniform thickness, and accordingly the shape of the base(base) is reflected on a light transmitting resin to be formed next sothat the light transmitting resin may have a uniform thickness.Furthermore, compared to a case where the light transmitting member isformed only using the light transmitting resin, it is possible to reducea volume of the light transmitting resin using the base, so that it ispossible to reduce an influence of the volume change in a process offorming the light transmitting resin. Accordingly, a space between thelight blocking substrate and the sensor substrate is filled with thelight transmitting member with a uniform thickness, so that it ispossible to uniformly dispose the light blocking substrate and thesensor substrate at a predetermined gap.

Application Example 3

In the imaging device according to the application example, it ispreferable that a predetermined gap between the sensor substrate and thelight blocking substrate be 50 μm or more, and the volume occupancy ofthe base in the light transmitting member be 50% or more.

The sensor substrate and the light blocking substrate are spaced apartfrom each other at a predetermined gap (50 μm or more) to arrange amicro-lens, the opening portion, and the photo-electric conversionelement on the same optical axis, and light of an inspection object(inspection light) traveling along the optical axis is caused to beincident on the photo-electric conversion element, and thereby it ispossible to inhibit light other than the inspection light obliquelytraveling with respect to the optical axis from being incident on thephoto-electric conversion element. Accordingly, in order to selectivelycause the inspection light to be incident on the photo-electricconversion element, it is preferable to uniformly dispose the sensorsubstrate and the light blocking substrate at a gap of 50 μm or more.

Therefore, between the sensor substrate and the light blockingsubstrate, it is necessary to form the light transmitting member with athickness corresponding to the gap. In the light transmitting resinconfiguring the light transmitting member, the volume change (curingshrinkage) occurs in the manufacturing process. In order to form thelight transmitting member at a uniform thickness, it is preferable toincrease the share of the base and to decrease the share of the lighttransmitting resin to reduce an influence of the volume change. That is,it is preferable to set the share of the base to 50% or more in thelight transmitting member to decrease the share of the lighttransmitting resin in the light transmitting member.

Application Example 4

In the imaging device according to the application example, it ispreferable that the base cover the sensing region to be formed on thesensor substrate.

In the sensing region of the sensor substrate, the photo-electricconversion element is changed to detect the inspection light. Thephoto-electric conversion element in the sensing region is covered usingthe base, and thereby it is possible to protect the photo-electricconversion element from a mechanical impact.

Application Example 5

In the imaging device according to the application example, it ispreferable that the light blocking substrate have the light transmittingsubstrate where the light blocking film is formed, and the refractiveindex of the light transmitting substrate be equal to the refractiveindex of the light transmitting member.

The detection light collected by the micro-lens sequentially passesthrough the opening portion of the light blocking substrate (lighttransmitting substrate) and the light transmitting member, and isallowed to be incident on the photo-electric conversion element of thesensor substrate. In this case, the refractive index of the openingportion (light transmitting substrate) is equal to the refractive indexof the light transmitting member, and thereby it is possible to inhibitinterfacial reflection in the boundary between the opening portion(light transmitting substrate) and the light transmitting member.Accordingly, it is possible to inhibit the attenuation of the inspectionlight by the interfacial reflection.

Application Example 6

In the imaging device according to the application example, it ispreferable that between the light blocking substrate and the lightcollecting substrate, the illumination substrate where the lightemitting element is disposed be disposed.

Even if the illumination substrate is disposed between the lightblocking substrate and the light collecting substrate, light emitted onthe sensor substrate side from the illumination substrate is blocked bythe light blocking substrate. Accordingly, it is possible to illuminatethe inspection object without illuminating the sensor substrate. As aresult, the imaging device illuminates the inspection object and detectslight reflected from the inspection object, so that it is possible tostably perform inspection even at a dark place without being influencedby external light. Furthermore, the illumination substrate is disposedbetween the light blocking substrate and the light collecting substrate,and thereby it is possible to inhibit a volume increase of the imagingdevice by the addition of the illumination substrate.

Application Example 7

According to this application example, there is provided an inspectionapparatus, including the imaging device according to the applicationexample, and a control unit performing inspection according to a resultof the detection of the imaging device.

In this case, the inspection apparatus includes the imaging devicedescribed in the application example, so that the inspection apparatusmay detect detection light with a high accuracy without being influencedby the external light and perform various inspections using the controlunit. For example, the inspection apparatus in the present applicationexample is mounted on a biosensor in a medical and health field such asa pulse rate monitor, a pulse oximeter, a blood glucose meter, and thelike, and thereby it is possible to provide the inspection apparatuswhich may detect necessary information with a high accuracy.Furthermore, a finger is emitted by the imaging device of the presentapplication example, and a vein image of the finger is captured with ahigh accuracy, and thereby it is possible to provide a biometricauthentication device as the inspection apparatus performing personalauthentication from a result of the detection. Furthermore, theinspection apparatus of the present application example may be appliedto an image reading apparatus such as image scanner, copier, facsimile,and bar code reader.

Application Example 8

According to this application example, in a method of manufacturing anelectronic device having a pair of substrates disposed to be opposite toeach other at a predetermined gap, there is provided a manufacturingmethod including: forming a base on one of the pair of substrates;coating an adhesive including a gap material forming a predetermined gaparound the base; coating a light transmitting resin material on thesurface of the base; disposing the pair of substrates at a predeterminedgap by bringing the other substrate of the pair of substrates in contactwith the light transmitting resin material to be superimposed on the onesubstrate; and solidifying the adhesive.

In a known method of forming the sealing material including the gapmaterial forming a predetermined gap in a frame shape, disposing a pairof substrates at the predetermined gap by the sealing material, andfilling the light transmitting resin material in a gap between the pairof substrates surrounded using the sealing material to solidify thelight transmitting resin material, a volume change (curing shrinkage)increases in a process of solidifying the light transmitting resinmaterial, so that it is difficult to dispose the pair of substrates atthe predetermined gap.

In the present Application Example, since the base is formed in the gapof the pair of substrates, compared to a case where the gap of the pairof substrates is filled with only the light transmitting resin material,it is possible to decrease a filling amount (volume) of the lighttransmitting resin material filling in the gap of the pair ofsubstrates. Accordingly, an influence of the volume change occurring ina solidification process of the light transmitting resin material may bereduced, so that it is possible to dispose the pair of substrates at apredetermined gap.

Application Example 9

In the manufacturing method according to the application example, it ispreferable that the volume of the light transmitting resin materialcoated in the coating of the light transmitting resin material, when thepair of substrates are superimposed each other at a predetermined gap,be smaller than the volume of the space surrounded by the pair ofsubstrates, the base and the adhesive.

In a state where the space surrounded by the pair of substrates, thebase, and the adhesive is filled with the light transmitting resinmaterial, the pair of substrates is pressed to have a predetermined gap.The filling amount of the light transmitting resin material (a coatingamount by coating the light transmitting resin material), when the pairof substrates are disposed at a predetermined gap, may be smaller thanthe volume of the space surrounded by the pair of substrates, the base,and the adhesive. Accordingly, when the pair of substrates are pressedto have a predetermined gap, it is possible to inhibit the lighttransmitting resin material from overflowing (run off) from the spacesurrounded by the pair of substrates, the base, and the adhesive.

Application Example 10

In the manufacturing method according to the application example, it ispreferable that the disposing of the pair of substrates at apredetermined gap be performed using a depressurized atmosphere.

In the disposing of the pair of substrates at a predetermined gap, theenclosed space surrounded by the pair of substrates, the base, and theadhesive is formed, and the middle of the enclosed space is filled withthe light transmitting resin material. The disposing of the pair ofsubstrates at a predetermined gap is performed using a depressurizedatmosphere, and accordingly it is possible to cause the enclosed spaceto have a negative pressure. After forming the enclosed space, if thepressure is changed from the depressurized atmosphere to atmosphericpressure, the inside of the enclosed space has a negative pressure, andthereby a large force uniformly acts in the enclosed space based on avoltage difference between the atmospheric pressure and the negativepressure. The adhesive has a gap material forming a predetermined gap,so that a predetermined gap is uniformly formed on the pair ofsubstrates by uniformly pressing the pair of substrate. Furthermore, thelight transmitting resin material is exposed to the depressurizedatmosphere, and thereby the light transmitting resin material isdeformed and air bubbles are inhibited from being mixed therein.

Application Example 11

In the manufacturing method according to the application example, it ispreferable that the adhesive be a photo-curable resin, and the lighttransmitting resin material be a thermo-curable resin.

The adhesive is formed in a region having a property of lighttransmission at a peripheral edge portion of the pair of substrates. Theadhesive is caused to be the photo-curable resin, and thereby, withoutreceiving an influence of heat (heat deformation), it is possible toquickly form a predetermined shape. On the other hand, the lighttransmitting resin fills the gap between the pair of substrates wherevarious light blocking patterns are formed, so that it is difficult tocompletely light-solidify the light transmitting resin by emitting lightonto the entire surface thereof. Therefore, the light transmitting resinmaterial is preferably the thermo-curable resin, and it is possible toentirely solidify the light transmitting resin material by performing aheat treatment. Furthermore, when performing thermo-curing on the lighttransmitting resin material, the pair of substrates is solidified usingthe light-cured adhesive, and thereby it is possible to inhibit the pairof substrates from being deformed by the heat treatment and to disposethe pair of substrates in the predetermined gap.

Application Example 12

In the manufacturing method according to the application example, it ispreferable that the predetermined gap of the pair of substrates be 50 μMor more, and in a total volume which is a sum of the volume of the basedisposed between the pair of substrates and the volume of the lighttransmitting resin material, the base be formed so as to have a 50% ormore volume occupancy.

In order to selectively detect inspection light, it is preferable todispose the sensor substrate and the light blocking substrate at a gapof 50 μm or more. Furthermore, the light transmitting resin disposedbetween the sensor substrate and the light blocking substrate is amember which has a volume change (curing shrinkage) in the manufacturingprocess, so that, in order to form the light transmitting member with auniform thickness, it is preferable to increase the share of the baseand to decrease the share of the light transmitting resin in the lighttransmitting member. That is, in the base and the light transmittingresin material disposed in the gap of the pair of substrates and thelight transmitting resin material, it is preferable that the volumeoccupancy of the base, which is the total volume provided by adding thevolume of the base and the volume of the light transmitting material, becaused to be 50% or more, and the volume of the light transmitting resinmaterial be smaller than the volume of the base.

Application Example 13

According to this application example, there is provided a method ofmanufacturing an electronic device having the pair of substratesdisposed to be opposite to each other at a predetermined gap. The methodincludes forming a base on one substrate of the pair of substrates,coating a light-transmitting resin material on the surface of the base,disposing the pair of substrates at a predetermined gap by bringing theother substrate of the pair of substrates into contact with the lighttransmitting resin material to be superimposed on the one substrate, andsolidifying the light transmitting resin material.

First, the base which has a smooth surface and a uniform thickness isformed on one of the pair of substrates. Next, if the surface of thebase is coated with the light transmitting resin material to besuperimposed on the other substrate of the pair of substrates, thesurface shape of the base (base) is reflected in the light transmittingresin material, and the light transmitting resin material has a smoothsurface and a uniform thickness the same as the base. Accordingly, boththe base and the light transmitting resin material have a uniformthickness, and thereby it is possible to uniformly form the gap betweenthe pair of substrates by disposing the base and the light transmittingresin material in the gap between the pair of substrates.

Application Example 14

In the manufacturing method according to the application example, it ispreferable that the light transmitting resin material be athermo-curable resin.

The pair of substrates has a light blocking pattern, so that it isdifficult to emit light to an entire surface of the light transmittingresin material, and if a photo-curable resin is used for the lighttransmitting resin material, it is difficult to be completelysolidified. Thus, the light transmitting resin material is preferably athermo-curable resin, and it is possible to completely solidify thelight transmitting resin material interposed between the pair ofsubstrates by performing a heat treatment.

Application Example 15

In the manufacturing method according to the application example, it ispreferable that the predetermined gap be 50 μm or more, and the base beformed so as to make a thickness be 90% or more of the predeterminedgap.

In order to selectively detect inspection light, it is preferable todispose the sensor substrate and the light blocking substrate at a gapof 50 μm or more. Furthermore, the light transmitting resin memberdisposed between the sensor substrate and the light blocking substratehas a volume change (curing shrinkage) in the manufacturing process. Onthe other hand, the base is processed to have a uniform thickness usinga resin. Thus, in order to form the light transmitting member in auniform thickness, it is preferable to increase the share of the base asmuch as possible and to decrease the share of the light transmittingresin material as much as possible in the light transmitting member.Specifically, it is preferable to set the share of the base to 90% ormore and the light transmitting resin material to less than 10%, and toreduce an influence of the volume change of the light transmitting resinmaterial.

Application Example 16

In the manufacturing method according to the application example, it ispreferable that the base be formed using the photo-curable resin.

If the base is coated with the photo-curable resin and left as it is fora constant time, the photo-curable resin flows so that the surface areamay be reduced using the surface tension and the weight of thephoto-curable resin. Specifically, the photo-curable resin in a statethat concave and convex are large immediately after coating (the surfacearea is large) flows in a direction to reduce the surface area, that is,in a direction to be a smooth surface. Furthermore, the photo-curableresin does not receive the influence of heat (heat deformation) in acuring process. That is, by emitting ultraviolet rays, it is possible toinhibit the influence of heat (heat deformation) and to solidify thephoto-curable resin having a smooth surface. Accordingly, using thephoto-curable resin, it is possible to form the base having a smoothsurface and a uniform thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is an exploded perspective view of an imaging device according toa first embodiment.

FIG. 2 is a cross-sectional view of the imaging device taken along aline II-II of FIG. 1.

FIG. 3 is a flowchart illustrating a method of manufacturing the imagingdevice according to the first embodiment in a process order.

FIGS. 4A to 4E are cross-sectional views of a main process taken along aline IV-IV of FIG. 1.

FIG. 5 is an exploded perspective view illustrating a configuration ofthe imaging device according to a second embodiment.

FIG. 6 is a cross-sectional view taken along a line VI-VI of FIG. 5.

FIG. 7 is a flowchart illustrating a method of manufacturing the imagingdevice according to the second embodiment in the process order.

FIGS. 8A to 8D are cross-sectional views of a main process taken along aline VIII-VIII of FIG. 5.

FIG. 9 is a schematic view illustrating a configuration of an inspectionapparatus.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following, with reference to the drawings, describes embodiments ofthe present invention. Such embodiments illustrate an aspect of thepresent invention, and without limiting the present invention, can bearbitrarily changed within a scope of technical concepts of the presentinvention. In addition, in following drawings, in order to set eachlayer and each part to a size which may be recognized on the drawings,each layer and each part are made differently from the actual scales.

First Embodiment

FIG. 1 is an exploded perspective view of an imaging device according toa first embodiment. FIG. 2 is a cross-sectional view of the imagingdevice taken along a line II-II of FIG. 1. First, referring to FIGS. 1and 2, a schematic configuration of an imaging device 1 according to theembodiment is described.

Overview of Imaging Device

The imaging device 1 according to the embodiment is an image sensoremitting light to an emitted body (not illustrated) to convert lightreflected from the emitted body into an electric signal. The imagingdevice 1 includes a light-emitting element 52 emitting the emitted bodyand a sensing region 5 where a photodiode 13 and the like as aphotoelectric conversion element detecting light (inspection light) ofan inspection object reflected from the emitted body is disposed. Theshape of the sensing region 5 is a square shape, and is illustrated bydashed lines in FIGS. 1 and 2.

Hereinafter, a direction along one side of the sensing region 5 close toa terminal 14 is set to a X axis direction, a direction along other twosides which are orthogonal to the one side and opposite to each other isset to a Y axis direction, and a width direction of the imaging device1, which is orthogonal to the X axis direction and the Y axis direction,is set to a Z axis direction.

As illustrated in FIGS. 1 and 2, in the imaging device 1, a sensorsubstrate 10, a member (a sealing material 20, a light transmittingmaterial 30) which forms a predetermined gap between the sensorsubstrate 10 and a light blocking substrate 40, the light blockingsubstrate 40, an illumination substrate 50, and a micro-lens array(hereinafter, referred to as MLA) substrate 60 are stacked in the Z axis(+) direction in this order. In addition, the light blocking substrate40 and the illumination substrate 50, and the illumination substrate 50and the MLA substrate 60 adhere to each other, respectively, using atransparent adhesive 63 (FIG. 2).

The sensor substrate 10 has a role of converting a reflected light fromthe emitted body into an electrical signal. The sensor substrate 10includes a sensor substrate main body 11, a photodiode 13 formed on asurface of a Z axis (+) direction side of the sensor substrate main body11, a circuit unit 12, and a terminal 14 and the like. The sensorsubstrate main body 11 may be an insulation substrate, and may be madeusing glass, quartz, resin, ceramic, and the like. The photodiode 13,for example, is configured to include a photo-electric conversionelement having a PIN type semiconductor layer as a photo-electricconversion layer, and thereby it is possible to detect light of a nearinfrared region. In the sensing region 5, the photodiode 13 is arrangedat equal gaps in the X direction and the Y direction, and the gap (arraypitch) is approximately 100 μm. The circuit unit 12, for example, isconfigured to include a complementary type transistor which has a nchannel type transistor and a P channel type transistor. The terminal 14is connected to an external circuit (not illustrated), and supplies acontrol signal from the external circuit to the circuit unit 12.

The sealing material 20 includes a gap material (not illustrated)forming a predetermined gap (approximately 100 μm) between the sensorsubstrate 10 and the light blocking substrate 40, and is disposed aroundthe sensing region 5 in a frame shape. Using the sealing material 20 inthe frame shape, the sensor substrate 10 and the light blockingsubstrate 40 are disposed at a gap of approximately 100 μm.

The light transmitting member 30 is configured to include a base 31 anda light transmitting resin 35, and is disposed over the sensing region 5between the sensor substrate 10 and the light blocking substrate 40. Thebase 31 is disposed on the sensor substrate 10 side and a thickness ofthe base 31 (length of the Z axis direction) is approximately 70 μm. Thebase 31 has a role of protecting the photodiode 13 disposed in thesensing region 5 of the sensor substrate 10 from a mechanical shock. Thelight transmitting resin 35 is disposed on the light blocking substrate40 side (between the base 31 and the light blocking substrate 40), and athickness of the light transmitting resin 35 is approximately 30 μm.Accordingly, in the sensing region 5 between the sensor substrate 10 andthe light blocking substrate 40, the light transmitting member 30 with athickness of 100 μm is disposed (filled), so that it is possible todispose the sensor substrate 10 and the light blocking substrate 40 at auniform gap (approximately 100 μm) in the sensing region 5.

Furthermore, between the sealing material 20 and the light transmittingmember 30, a void 39 (refer to FIG. 2) is formed. The void 39 is astorage space for storing the light transmitting resin 35 overflowingfrom the base 31 in a manufacturing process to be described below, andhas a role of inhibiting the light transmitting resin 35 from protrudingto the outside of the sealing material 20.

A configuration may be provided in which the base 31 is disposed on thelight blocking substrate 40 side and the light transmitting resin 35 isdisposed on the sensor substrate 10 side.

The light blocking substrate 40 is configured to include a lightblocking substrate main body 41 and a light blocking film 42 disposed ona surface of Z axis (−) direction side of the light blocking substratemain body 41. The light blocking substrate main body 41 is a lighttransmitting substrate, for which glass, quartz, resin, and the like maybe used. The light blocking film 42 may be a film having a property oflight transmission, for which a metal film, for example, Cr and thelike, may be used. In the light blocking film 42, an opening portion 43is formed at a position corresponding to the photodiode 13, andinspection light reflected from the emitted body passes through theopening portion 43 to be incident on the photodiode 13.

As described above, the light transmitting member 30 is disposed betweenthe sensor substrate 10 and the light blocking substrate 40, andinspection light passing through the opening portion 43 is caused topass through the light transmitting member 30 to be incident on thephotodiode 13. The refractive index of the light transmitting member 30is substantially equal to the refractive index of the light blockingsubstrate main body 41. Therefore, interfacial reflection at a boundarybetween the light blocking substrate main body 41 and the lighttransmitting member 30 is inhibited in the opening portion 43, andthereby it is possible to inhibit attenuation of the inspection light.

The illumination substrate 50 includes an illumination substrate mainbody 51, a light-emitting element 52 formed on a surface of a Z axis (+)direction side of the illumination substrate main body 51, and the like.The light-emitting element 52 is an organic electroluminescence elementwhich emits light of the near-infrared region in the Z axis (+)direction, and is configured to have an anode (not illustrated), alight-emitting functioning layer (not illustrated), and a cathode (notillustrated). In addition, the light-emitting element 52 is arranged ina matrix in the sensing region 5 to uniformly emit the emitted body.

A MLA substrate 60 is an example of “light collecting substrate”, andhas a role of collecting light of an inspection object reflected fromthe emitted body and leading the light to the photodiode 13. The MLAsubstrate 60 is configured to include a MLA substrate main body 61, amicro-lens 62 formed on a surface of the Z axis (−) direction side ofthe MLA substrate main body 61, and the like. The MLA substrate mainbody 61 is a light transmitting substrate, for which glass, quartz,resin, and the like may be used. The micro-lens 62 is a spherical lensformed by a transparent resin or glass or a non-spherical lens, and isdisposed in a matrix shape in the sensing region 5. The micro-lens 62may be formed using a reflow method, the halftone mask method, amicro-lens method, a molding process method, and the like.

Outline of Sensing Region

Next, outline of the sensing region 5 (a detection method of inspectionlight and the like) will be described.

In the sensing region 5, the photodiode 13, the opening portion 43, thelight-emitting element 52, the micro-lens 62, and the like are arrangedin a matrix shape so as to be one to one corresponding to each other,respectively. An optical axis 6 illustrated with a dashed line in FIGS.1 and 2 is a virtual line connecting the center of one micro-lens 62 aout of a plurality of arranged micro-lenses with the center of theopening portion 43 and is parallel to the Z axis direction. In FIG. 2,an arrow sign with a numeral no. 7 indicates inspection light(hereinafter, referred to as inspection light 7) which is incident on aphotodiode 13 out of the plurality of arranged photodiodes. Thephotodiode 13 corresponds to the micro-lens 62 a. An arrow sign with anumeral number 8 indicates light traveling on an optical path connectingan adjacent micro-lens 62 b and the photodiode 13, that is, light inaddition to inspection light 7 traveling from the adjacent micro-lens 62b to the photodiode 13 (hereinafter, referred to as redundant light 8).

The micro-lens 62 a, an opening portion 43, and the photodiode 13 aredisposed on the optical axis 6, and the light-emitting element 52 isdisposed at a position spaced apart from the optical axis 6. As aresult, inspection light 7 collecting light using the micro-lens 62 a isnot blocked by the light-emitting element 52. Additionally, a regionintersecting with the optical axis 6 of the illumination substrate 50 (aregion through which the inspection light 7 passes) has a property oflight transmission, and the inspection light 7 is allowed to passthrough (go through) the illumination substrate 50.

As illustrated in FIG. 2, light which is collected using the micro-lens62 a and travels along the optical axis 6 is set to inspection light 7.That is, the inspection light 7 passes through the micro-lens 62 a ofthe MLA substrate 60, a light transmitting region of the illuminationsubstrate 50, the opening portion 43 of the light blocking substrate 40,and the light transmitting member 30 to be incident on the photodiode 13of the sensor substrate 10. In other words, light which is incident onthe micro-lens 62 a from the above of the micro-lens 62 a (Z axisdirection) travels along the optical axis 6 to be incident on thephotodiode 13. That is, in the sensing region 5, it is possible to imagethe image information of the object to be incident on the micro-lens 62a from the Z axis direction.

The micro-lens 62 a is a so-called convex lens, and light collectedusing the micro-lens 62 a (image information of an object) is adapted toform an image on a light sensing surface of the photodiode 13.Furthermore, the light blocking substrate 40 is disposed approximately100 μm apart from the sensor substrate 10 using the light transmittingmember 30. A gap between the light blocking substrate 40 and the sensorsubstrate 10 is equal to an array pitch of the photodiode 13(approximately 100 μm) which is arranged in the sensing region 5 of thesensor substrate 10. In a state where the sensor substrate 10 and thelight blocking substrate 40 are disposed to be opposite to each other ata gap of approximately 100 μm, an opening size of the opening portion 43is made to the smallest size that the inspection light 7 collected usingthe micro-lens 62 a may pass through the opening portion 43. As aresult, the light 8 not necessary to be entered from the adjacentmicro-lens 62 b is reflected (light blocked) by the light blocking film42 of the light blocking substrate 40, and is inhibited from beingincident on the photodiode 13. In addition to the redundant light 8,there are lights besides the inspection light 7. These lights besidesthe inspection light 7 are all lights traveling in an oblique directionwith respect to the optical axis 6, and are blocked by the lightblocking film 42 of the light blocking substrate 40 to be inhibited frombeing incident on the photodiode 13. Light besides the inspection light7 is a detection noise of the photodiode 13, so that it is possible toimage the image information with less detection noise and high accuracyusing the photodiode 13 by blocking the light besides the inspectionlight 7.

Accordingly, in order to block the redundant light 8 and allow theinspection light 7 to be selectively incident on the photodiode 13, itis important to dispose the light blocking substrate 40 and the sensorsubstrate 10 in parallel at a gap of an array pitch of the photodiode 13or more.

Due to the bending and the like of the substrate, if there occurs aregion where the light blocking substrate 40 is obliquely disposed withrespect to the sensor substrate 10, in the region, there is an errorthat the photodiode 13 is not disposed on the optical axis 6 and theinspection light 7 is not incident. In order to avoid theabove-mentioned error, it is preferable to form a gap between the lightblocking substrate 40 and the sensor substrate 10 with an accuracy of±5% or less.

In the embodiment, the array pitch of the photodiode 13 is approximately100 μm, and the light blocking substrate 40 and the sensor substrate 10are disposed in parallel at a uniform gap of approximately 100 μm. Thepresent invention has an appropriate manufacturing method to dispose thelight blocking substrate 40 and the sensor substrate 10 at a uniformgap, and therefore an outline thereof will be described below.

Outline of a Manufacturing Method of Disposing Light Blocking Substrateand Sensor Substrate at a Uniform Gap

FIG. 3 is a flowchart illustrating a manufacturing method of disposingthe light blocking substrate and the sensor substrate at a uniform gapin a process order. FIG. 4A to 4E are cross-sectional views of a mainprocess taken along a line of IV-IV of FIG. 1. In FIG. 4, the sensingregion 5 is illustrated by dashed lines so that a position of acomponent configured using each process may be known. Hereinafter, theoutline of a manufacturing method according to the present embodimentwill be described referring to FIGS. 3 and 4.

In a process of step S1 (FIG. 3), by coating a first ultraviolet(hereinafter, referred to as UV) curable resin 32 on the sensorsubstrate 10 using a dispenser, a base precursor 33 is formed. The firstUV curable resin 32 is an example of “photo-curable resin”, and isconfigured to have a UV curable epoxy resin with a viscosity ofapproximately 500 cP (mPa·s). The first UV curable resin 32 covers thesensing region 5 and is coated to the periphery of the sensing region 5to form the base precursor 33.

FIG. 4A illustrates a state of right after coating of the first UVcurable resin 32. As illustrated in FIG. 4A, in right after coating ofthe first UV curable resin 32, the first UV curable resin 32 coated andformed in a line along a X axis direction is arranged in a multiple wayin a Y axis direction to form the base precursor 33. Therefore, the baseprecursor 33 (a surface on the Z axis (+) direction side) hasconcave-convex surface, and a thickness (length in the Z axis direction)of the surface is periodically changed.

In a process of step S2 (FIG. 3), the coated first UV curable resin 32is left as it is for a certain time and allowed to flow the first UVcurable resin 32 to perform leveling for making the thickness of thebase precursor 33 uniformly. The thickness of the base precursor 33depends on an amount of coating of the first UV curable resin 32. In aprocess of curing the first UV curable resin to be described below, thefirst UV curable resin is contracted in volume. Considering the volumecontraction, the base precursor 33 is coated and formed so as to bethicker than the thickness of the base 31 (approximately 70 μm).Specifically, the thickness of the base precursor 33 is approximately 74μm.

FIG. 4B illustrates a state of the base precursor 33 after beingleveled. In a process of step S2, in order to minimize the area of thesurface of the base precursor 33 according to the surface tension andthe weight of the first UV curable resin 32, the first UV curable resin32 flows. Therefore, the concave and convex on the surface of the baseprecursor 33 are reduced so that the base precursor 33 may be configuredto have a smooth (flat) surface. Then, the base precursor 33 has auniform thickness after leveling.

In a process of step S3 (FIG. 3), UV light is emitted to the baseprecursor 33 and the first UV curable resin 32 is cured (solidifying) toform the base 31. As a result, the base precursor 33 in a shapeillustrated in FIG. 4B is the base 31. As illustrated in FIG. 4B, thebase 31 has a cross-section in a shape of trapezoidal where an edge of aside in contact with the sensor substrate 10 is caused to be long. Inaddition, the end portions of the base 31 are in a tapered shape, whichare inclined with respect to the Z axis (+) direction. The baseprecursor 33 is contracted in volume when cured by the UV light and thethickness of the base 31 is caused to be approximately 70 μm.

A resin material forming the base precursor 33 may be either athermo-curable resin or a resin having thermo-curability andphoto-curability. Even in a case of using these resins, the sameleveling process is performed, and these resins are allowed to flow soas to minimize the area of the surface according to the surface tensionand the weight of the resin, and thereby it is possible to form thebased precursor 33 having a smooth (flat) surface. Even in a case ofusing either the thermo-curable resin or the resin havingthermo-curability and photo-curability, the same volume contractionoccurs when the resin is cured. Accordingly, it is necessary to form thebase precursor 33 in anticipation of the volume contraction so that thethickness of the base 31 may be a predetermined size (approximately 70μm).

In a process of step S4 (FIG. 3), a second UV curable resin 21 is coatedto the periphery of the sensing region 5 on the sensor substrate 10using a dispenser so as to surround the base 31. The second UV curableresin 21 includes a gap material of 100 μm (not illustrated), and is anexample of “adhesive including a gap material having a predeterminedgap”. Specifically, the second UV curable resin 21 is configured to havea UV curable epoxy resin with high viscosity of approximately 600,000cP. The thickness of the second UV curable resin 21 (length in the Zaxis direction) is approximately 140 μm, and is pressed and solidifiedin a process described below to be the sealing material 20 having athickness of approximately 100 μm.

FIG. 4C is a view illustrating a state after coating the second UVcurable resin 21. As illustrated in FIG. 4C, the second UV curable resin21 is formed in a frame shape to enclose the sensing region 5. Thesecond UV curable resin 21 is a resin with high viscosity (approximately600,000 cp). Even if the second UV curable resin is formed with athickness of 140 μm using the gap material dispersed therein, it ispossible to inhibit a change in shape (a change in thickness).

In a process of step S5 (FIG. 3), using the dispenser, thethermo-curable resin 36 is coated on the surface of the base 31 (a sidesurface of the light blocking substrate 40). The thermo-curable resin 36is an example of “light transmitting resin material”. In addition, theviscosity of the thermo-curable resin 36 is approximately 300 cP.

FIG. 4D is a view illustrating a state after coating the thermo-curableresin 36. The thermo-curable resin 36 has a low viscosity (approximately300 cP), so that the thermo-curable resin may flow (spread) on thesurface of the base 31 using the surface tension and the weight of thethermo-curable resin 36. As a result, as illustrated in FIG. 4D, thethermo-curable resin 36 is formed to cover the surface of the base 31. Acoating amount (dropping amount) of the thermo-curable resin 36 will bedescribed.

In a process of step S6 (FIG. 3), the light blocking substrate 40 andthe sensor substrate 10 are superimposed (bonded) on a predeterminedposition. The superimposing process is performed with the pressure ofexternal atmosphere decreased (depressurized atmosphere), and the lightblocking substrate 40 and the sensor substrate are superimposed at apredetermined position while being pressed. In a process of step S6, anenclosed space surrounded by the sensor substrate 10, the light blockingsubstrate 40, and the second UV curable resin 21 is formed. In addition,the enclosed space is filled with the thermo-curable resin 36.

In a process of step S7 (FIG. 3), UV light is emitted by changingexternal atmosphere from the depressurized state to the atmosphericpressure and the second UV curable resin 21 is cured (solidified) toform the sealing material 20. The enclosed space formed by thedepressurized atmosphere of step S6 (a space filled with thethermo-curable resin 36) has a negative pressure compared to atmosphericpressure, so that if external atmosphere is changed from a depressurizedstate to atmospheric pressure, a large pressure equivalent to a pressuredifference between a pressure of the depressurized atmosphere (negativepressure) and atmospheric pressure uniformly acts in the enclosed space.That is, if the external atmosphere is changed from the depressurizedstate to the atmospheric pressure, a large force to be describeduniformly acts between the light blocking 40 and the sensor substrate10, and the second UV curable resin 21 is compressed to the thickness ofthe gap material (approximately 100 μm). The compressed second UVcurable resin 21 is solidified by UV light to form the sealing material20 forming a predetermined gap (approximately 100 μm) between the sensorsubstrate 10 and the light blocking substrate 40.

FIG. 4E is a view illustrating a state after changing the externalatmosphere to the atmospheric pressure in a process of step S7. Asdescribed above, a large force uniformly acts between a surface on the Zaxis direction side of the light blocking substrate 40 and a surface onthe Z axis direction side of the sensor substrate 10, and a gap betweenthe light blocking substrate 40 and the sensor substrate 10 is changedfrom approximately 140 μm to approximately 100 μm. At this time, a gapbetween the surface of the base 31 and the light blocking substrate 40is changed from approximately 70 μm to approximately 30 μm, and thethermo-curable resin 36 filled between the surface of the base 31 andthe light blocking substrate 40 protrudes to the periphery of the base31. The thermo-curable resin 36 overflowing from the surface of the base31 stays at the void 39 between the sealing material 20 (the second UVcurable resin 21) and the base 31, and in order not to protrude out ofthe sealing material 20 (the second UV curable resin 21), a coatingamount of the thermo-curable resin 36 is set in the step S5.

Specifically, the coating amount of the thermo-curable resin 36 in theprocess of step 5, when the sensor substrate 10 and the light blockingsubstrate 40 are disposed in a predetermined gap (approximately 100 μm)in a process of step S7, is set to be smaller than the volume of a spacesurrounded by the sensor substrate 10, the light blocking substrate 40,the sealing material 20, and the base 31. As a result, thethermo-curable resin 36 overflowing from the surface of the base 31stays at the void 39 between the sealing material 20 and the base 31 notto protrude out of the sealing material 20.

If the thermo-curable resin 36 protrudes out of the sealing material 20,there is a possibility that the terminal 14 is contaminated and anelectrical connection between an external circuit (not illustrated) andthe terminal 14 is inhibited. As described above, in a process of stepS5, the coating amount of the thermo-curable resin 36 is set to anamount that the thermo-curable resin 36 does not protrude out of thesealing material 20, and thereby it is possible to inhibit the terminal14 from being contaminated. Furthermore, the void 39 formed between thesealing material 20 and the base 31 has a role of storage for storingthe thermo-curable resin 36 overflowing from the surface of the base 31in the process of step S7, and the void 39 is an important component forthe thermo-curable resin 36 not to protrude out of the sealing material20. That is, in order to form the void 39, in the process of step S4, itis preferable to coat the second UV curable resin 21 which is aprecursor of the sealing material 20 apart 0.3 mm to 1 mm from the base31.

In a process of step S8 (FIG. 3), a heat treatment is performed, thethermo-curable resin 36 is cured (solidified), the light transmittingresin 35 with a thickness of approximately 30 μm is formed between thebase 31 and the light blocking substrate 40. The refractive index of thelight transmitting resin 35 and the refractive index of the base 31 aresubstantially equal to the refractive index of the light blockingsubstrate main body 41. Accordingly, at the boundary (interface) betweenthe light blocking substrate main body 41 and the light transmittingresin 35, and the boundary between the light transmitting resin 35 andthe base 31, it is possible to inhibit interfacial reflection based onthe difference in a refractive index. Furthermore, the thermo-curableresin 36 is coated using a depressurized atmosphere, so that it ispossible to inhibit an air bubble from being mixed into thethermo-curable resin 36, that is, to inhibit an air bubble from beingmixed into the light transmitting resin 35. If the air bubble isinhibited from being mixed into the light transmitting resin 35, it ispossible to inhibit the interfacial reflection at the boundary betweenthe air bubble and the light transmitting resin 35 based on thedifference in a refractive index.

In addition, refractive index of a transparent adhesive 63, refractiveindex of a MLA substrate main body 61, refractive index of theillumination substrate main body 51, and refractive index of the lightblocking substrate main body 41 disposed at a gap between the MLAsubstrate 60 and the illumination substrate 50, and a gap between theillumination substrate 50 and the light blocking substrate 40 are equalto each other, so that the same interfacial reflection is inhibited. Inaddition, in the transparent adhesive 63, the first UV curable resin 32,the second UV curable resin 21, and the thermo-curable resin 36, adefoamation process is performed in the depressurized atmosphere, sothat the mixture of the air bubble is inhibited.

In the present invention, the sealing material 20 forming apredetermined gap after forming the base 31 is formed to decrease afilling amount of the thermo-curable resin 36 filling between the lightblocking substrate 40 (base 31) and the sensor substrate 10.Accordingly, it is possible to reduce volume contraction of thethermo-curable resin 36, which occurs when the thermo-curable resin 36is cured in a process of step S8. As a result, an influence caused bythe volume contraction (warp of substrate) is reduced, and even if thelight blocking substrate 40 and the sensor substrate 10 are disposed ata big gap of approximately 100 μm, the warp of the light blockingsubstrate 40 or the sensor substrate 10 are reduced. Accordingly, it ispossible to dispose the light blocking substrate 40 and the sensorsubstrate 10 at a uniform gap. Furthermore, at the periphery of thethermo-curable resin 36, the void 39 is formed, and thereby theinfluence of the volume shrinkage occurring in a solidification processof the thermo-curable resin 36 is eased also by the void 39.

Accordingly, in order to dispose the light blocking substrate 40 and thesensor substrate 10 at a uniform gap, in a space surrounded by thesensor substrate 10, the light blocking substrate 40, and the sealingmaterial 20, it is important to initially form the base 31 to decreasethe filling amount of the thermo-curable resin 36 filling in the space.

In a process of step S3 (FIG. 3) of forming the base 31, the volumecontraction of the first UV curable resin 32 forming the base 31 occurs.However, the base 31 is formed before the process of step S6 of forminga predetermined gap, so that the volume contraction does not influencethe predetermined gap.

Furthermore, in a volume of a space surrounded by the sensor substrate10, the light blocking substrate 40, and the sealing material 20, thatis, a volume of a space where the light transmitting member 30 isdisposed, the base 31 is formed so that the volume occupancy of the base31 may be 50% or more, the thermo-curable resin 36 is filled so that thevolume occupancy of the thermo-curable resin 36 may be less than 50% todecrease the filling amount of the thermo-curable resin 36. Accordingly,influence of the volume contraction occurring in the solidificationprocess of the thermo-curable resin 36 are reduced, and it is possibleto dispose the light blocking substrate 40 and the sensor substrate 10at a predetermined gap (approximately 100 μm).

As the volume occupancy of the thermo-curable resin 36 becomes smaller,the volume contraction becomes smaller in the solidification process ofthe thermo-curable resin 36. It is possible to dispose the sensorsubstrate 10 and the light blocking substrate 40 at a more uniform gap,and thereby it is preferable that the volume occupancy of the base 31 belarger and the volume occupancy of the thermo-curable resin 36 besmaller.

In addition, it is also possible to form the base 31 with a thickness of100 μm or more. However, using liquid of the first UV curable resin 32and the like which forms the base precursor 33, it is difficult to makethe base 32 in a predetermined form as the thickness (film thickness) ofthe base 31 becomes larger. Based on (In consideration of) manufacturingcondition of the base 31, the thickness of the base 31 is preferred tobe 100 μm or less.

As described above, according to the imaging device 1 related to thepresent embodiment, the following effects can be obtained.

(1) The light blocking substrate 40 and the sensor substrate 10 aredisposed at a predetermined gap (approximately 100 μm) which is suitablefor the inspection light 7 to be selectively incident on the photodiode13, and thereby it is possible to inhibit light in addition to theinspection light 7 which is a detection noise. Accordingly, it ispossible to provide the imaging device 1 where detection may beperformed with a high accuracy and less noise components.

(2) In a space surrounded by the sensor substrate 10, the light blockingsubstrate 40, and the sealing material 20, the base 31 is formed, andthe filling amount of the thermo-curable region 36 filled in the spacebecomes smaller, so that influence of the volume contraction (warp ofthe substrate) occurring in a solidification process of thethermo-curable resin 36 is caused to be small, so that it is possiblereduce a change in a gap between the light blocking substrate 40 and thesensor substrate 10 (warp of substrate).

(3) Furthermore, the base 31 is formed before a process of forming apredetermined gap at the light blocking substrate 40 and the sensorsubstrate 10, so that the volume contraction occurring in a process offorming the base 31 may avoid influencing a gap between the lightblocking substrate 40 and the sensor substrate 10.

(4) A process of superimposing the light blocking substrate 40 and thesensor substrate 10 is performed using the depressurized atmosphere, sothat it is possible to inhibit an air bubble from being mixed into thethermo-curable resin 36 (light transmitting resin 35).

(5) Furthermore, the thermo-curable resin 36 is filled, and an enclosedspace formed by the light blocking substrate 40, the sensor substrate10, and the sealing material 20 is a negative pressure. If the externalatmosphere is changed from the depressurized atmosphere to theatmospheric pressure, in the enclosed space, a large force uniformlyacts based on a pressure difference between the negative pressure andthe atmospheric pressure, and thereby it is possible to dispose thelight blocking substrate 40 and the sensor substrate 10 at apredetermined gap.

(6) Refractive index of the light transmitting resin 35, refractiveindex of the base 31, an refractive index of the light blockingsubstrate main body 41 are substantially equal to each other.Accordingly, in the boundary (interface) between the light blockingsubstrate main body 41 and the light transmitting resin 35, and theboundary between the light transmitting resin 35 and the base 31, it ispossible to inhibit interfacial reflection based on the difference in arefractive index.

(7) A coating amount of the thermo-curable resin 36 is set to be smallerthan a space surrounded by the sensor substrate 10, the light blockingsubstrate 40, the base 31, and the sealing material 20, so that it ispossible to inhibit the thermo-curable resin 36 from protruding from thespace, that is, the sealing material 20.

In addition, the void 39 is formed between the sealing material 20 andthe base 31, so that it is possible to store the thermo-curable resin 36in the void 39 not to protrude from the sealing material 20.Furthermore, using the void 39, it is possible to ease the influence ofvolume contraction occurring in the solidification process of thethermo-curable resin 36.

In order to make the sensing region 5 smaller and denser, it isnecessary to further reduce an array pitch of the photodiode 13.Specifically, the array pitch of the photodiode 13 of the presentembodiment is approximately 100 μm, but in order to make the sensingregion 5 much smaller and denser, it is preferable to reduce the arraypitch of the photodiode 13 to approximately 50 μm. In this case, it ispreferable to dispose the light blocking substrate 40 and the sensorsubstrate 10 at a gap of approximately 50 μm or more. According tocoating of a manufacturing method of the present embodiment, it ispossible to dispose the light blocking substrate 40 and the sensorsubstrate 10 at a uniform gap of approximately 50 μm or more.

In addition, even in a case where the light blocking substrate 40 andthe sensor substrate 10 are disposed at a gap described in the presentembodiment or more (gap of approximately 100 μm or more), by applyingthe manufacturing method of the present embodiment, it is possible todispose the light blocking substrate 40 and the sensor substrate 10 at auniform gap.

Furthermore, in addition to the above-mentioned imaging device 1, themanufacturing method of the present embodiment may be applied to amanufacturing method of an electronic device having a pair of substratesformed at a predetermined gap, for example, a manufacturing method ofattaching a touch panel to an electro-optical device such as a liquidcrystal display device and the like, or a manufacturing method ofattaching a dust-proof glass to the electro-optical device as a lightbulb in a use of a projector.

Embodiment 2

FIG. 5 is an exploded perspective view showing a configuration of animaging device 2 according to an embodiment 2, and corresponds toFIG. 1. FIG. 6 is a cross-sectional view taken along a line of VI-VI ofFIG. 5, and corresponds to FIG. 2. Hereinafter, referring to FIGS. 5 and6, the imaging device 2 according to the present embodiment will bedescribed mainly on the difference from the embodiment 1. In addition,with regard to a configuration part the same as the embodiment 1, thesame reference numeral is given to omit a duplicated description.

Outline of Imaging Device

In the imaging device 1 according to the embodiment 1, in order todispose the sensor substrate 10 and the light blocking substrate 40 at apredetermined gap, the sealing material 20 and the light transmittingmember 30 (the base 31, the light transmitting resin 35) are disposedbetween the sensor substrate 10 and the light blocking substrate 40(refer to FIGS. 1 and 2).

As illustrated in FIGS. 5 and 6, in an imaging device 2 according to thepresent embodiment, the light transmitting member 30 (the base 31, thelight transmitting resin 35) is disposed between the sensor substrate 10and the light blocking substrate 40, and the sealing material 20 in theembodiment 1 is not disposed, which is different from the embodiment 1.

Furthermore, the thickness of composition materials of the lighttransmitting member 30 (the length of Z axis direction), that is, thethickness of the base 31 and the thickness of the light transmittingresin 35, is different from in the embodiment 1. In the imaging device 1according to the embodiment 1, the thickness of the base 31 isapproximately 70 μm, and the thickness of the light transmitting resin35 is approximately 30 μm. In the imaging device 2 according to thepresent embodiment, the thickness of the base 31 is approximately 90 μm,and the thickness of the light transmitting resin 35 is approximately 10μm. That is, compared to the embodiment 1, the thickness (volume) of thebase 31 is larger, and the thickness (volume) of the light transmittingresin 35 becomes smaller.

Outline of Manufacturing Method of Disposing Light Blocking Substrateand Sensor Substrate at a Uniform Gap

FIG. 7 is a flowchart illustrating a manufacturing method of disposingthe light blocking substrate and the sensor substrate at a uniform gapin a process order, and corresponds to FIG. 3. FIGS. 8A to 8D arecross-sectional views of a main process taken along a line of VIII-VIIIof FIG. 5, and correspond to FIGS. 4A to 4E.

In the present embodiment, a process of forming the sealing material 20,that is, a process of step S4 and a process of step S7 (refer to FIG. 3)according to the embodiment 1, is omitted. Hereinafter, an outline ofthe process of manufacturing the imaging device 2 according to thepresent embodiment will be described referring to FIGS. 7 and 8.

In the process of step S1 (FIG. 7), the sensor substrate 10 is coatedwith the first UV curable resin 32 using a dispenser to form the baseprecursor 33.

FIG. 8A illustrates a state immediately after coating the first UVcurable resin 32. As illustrated in FIG. 8A, in immediately aftercoating of the first UV curable resin 32, a plurality of the first UVcurable resin 32 in a line shape coated and formed along the X axisdirection is disposed in the Y axis direction, and the base precursor 33is formed. The surface of the base precursor 33 (the surface on the Zaxis (+) direction side) has concave and convex portions, and thethickness (the length of the Z axis direction) is periodically changed.

In the process of step S2 (FIG. 7), the coated first UV curable resin 32is disposed for a predetermined time and is allowed to flow to performleveling which makes the thickness of the base precursor 33 uniform.

FIG. 8B is a view illustrating a state of the base precursor 33 afterthe leveling. As illustrated in FIG. 8B the first UV curable resin 32flows so that the surface area may be minimized by the surface tensionand the weight of the first UV curable resin 32. As a result, the baseprecursor 33 has a flat surface and a uniform thickness. The thicknessof the base precursor 33 is approximately 95 μm, and the base precursor33 is contracted in volume in a process of solidifying the first UVcurable resin 32 to be described below to be the base 31 with thethickness of approximately 90 μm. In addition, by adjusting a coatingamount of the first UV curable resin 32, it is possible to adjust thethickness of the base precursor 33.

In the process of step S3 (FIG. 7), the UV light is emitted and thefirst UV curable resin 32 is cured (solidified) to form the base 31. Asdescribed above, since the first UV curable resin 32 is contracted involume in the solidification process, the base precursor 33 with thethickness of approximately 95 μm becomes the base 31 with the thicknessof approximately 90 μm.

In the process of step S5 (FIG. 7), using the dispenser, the surface ofthe base 31 is coated with the thermo-curable resin 36. The viscosity ofthe thermo-curable resin 36 is approximately 300 cP.

FIG. 8C is a view illustrating a state after coating the thermo-curableresin 36. As illustrated in FIG. 8C, the thermo-curable resin 36 has alow viscosity (approximately 300 cP), so that the thermo-curable resin36 coated on the base 31 is spread over by the surface tension and theweight of the thermo-curable resin 36 to cover the surface of the base31.

In the process of step S6 (FIG. 7), the light blocking substrate 40 issuperimposed on a predetermined position of the sensor substrate 10(bonded), and is pressed so that a gap between the light blockingsubstrate 40 and the sensor substrate 10 (the thickness of thethermo-curable resin 36) may be approximately 11 μm. These processes areperformed using the depressurized atmosphere. If the light blockingsubstrate 40 and the sensor substrate 10 are pressed, the thermo-curableresin 36 protrudes from between the light blocking substrate 40 and thebase 31. If the thermo-curable resin 36, which protrudes from betweenthe light blocking substrate 40 and the base 31, reaches a terminal 14,it is difficult to be electrically connected to an external circuit (notillustrated). Therefore, it is necessary to adjust the coating amount ofthe thermo-curable resin 36 to the extent that the thermo-curable resin36 does not protrude to the terminal 14 in the process of step S5.

By performing the process of step S6 using the depressurized atmosphere,it is possible to inhibit an air bubble from being mixed into thethermo-curable resin 36. In addition, when using the thermo-curableresin 36 which is sufficiently de-foamed, the process of step S6 may beperformed at the atmospheric pressure.

In the process of step S8 (FIG. 7), the heat treatment is performed andthe thermo-curable resin 36 is cured (solidified) to form the lighttransmitting resin 35 between the base 31 and the light blockingsubstrate 40. As described above, the thermo-curable resin 36 iscontracted in volume in the solidification process, so that thethermo-curable resin 36 with the thickness of approximately 11 μm may bethe light transmitting resin 35 with the thickness of approximately 10μm.

FIG. 8D is a view illustrating a state after performing the process ofstep S8. The light transmitting resin 35 is formed so as to cover thebase 31 between the light blocking substrate 40 and the base 31. Thethickness of the light transmitting member 30 is approximately 100 μm.The gap between the light blocking substrate 40 and the sensor substrate10 (approximately 100 μm) is formed by the base 31 with the thickness ofapproximately 90 μm and the light transmitting resin 35 with thethickness of approximately 10 μm.

In the present embodiment, most of the gap between the light blockingsubstrate 40 and the sensor substrate 10 is formed by the base 31.Specifically, the thickness of the base 31 is set to be 90% of the gapbetween the light blocking substrate 40 and the sensor substrate 10.Accordingly, in order to dispose the light blocking substrate 40 and thesensor substrate 10 at a predetermined gap, the base 31 functions animportant role.

Accordingly, in the present embodiment, it is important to form the baseprecursor 33 for forming the base 31 at a uniform thickness. In order toform the base precursor 33 at a uniform thickness on the sensorsubstrate 10, in the process of step S1 and the process of step S2, itis important to maintain the sensor substrate 10 in a horizontal state,and to coat the first UV curable resin 32 on the sensor substrate 10 toflow (perform leveling). If the sensor substrate 10 is obliquelyinclined, the first UV curable resin 32 obliquely flows. Accordingly,the thickness of the base precursor 33 is not uniform. A horizontalsurface of the sensor substrate 10 is coated with the first UV curableresin 32, and the base 31 (base precursor 33) has a uniform thickness byperforming leveling.

The share of the light transmitting resin 35 in the gap between thelight blocking substrate 40 and the sensor substrate 10 is less thanapproximately 10% and becomes smaller than in the embodiment 1, andthereby it is possible to reduce the influence caused by a change inthickness of the light transmitting resin 35. Specifically, it ispossible to reduce volume contraction occurring in a process of formingthe light transmitting resin 35 by solidifying the thermo-curable resin36. In addition, in the process of step S6, the thermo-curable resin 36filling in a space between the surface of the base 31 and the lightblocking substrate 40 is pressed to be a predetermined thickness. Thepressing may be a technical pressing or a pressing by the weight of thelight blocking substrate 40. The filling amount of the thermo-curableresin 36 is small, so that a change in the thickness of thethermo-curable resin 36 using the pressing process is acceptable.

Thus, in the present embodiment, 90% or more in the gap between thelight blocking substrate 40 and the sensor substrate 10 is occupied bythe base 31, the base 31 is formed at a uniform thickness, and thereby achange (variation) in the gap between the light blocking substrate 40and the sensor substrate 10 is inhibited at 10% or less (±5% or less).Accordingly, it is possible to dispose the light blocking substrate 40and the sensor substrate 10 at a predetermined gap. That is, the base 31is thicker than in the embodiment 1, so that, even without forming thesealing material 20 which is in the embodiment 1, it is possible todispose the light blocking substrate 40 and the sensor substrate 10 at apredetermined gap.

As described above, according to the imaging device 2 related to thepresent embodiment, in addition to effects (1), (3), (4), and (6) in theembodiment 1, it is possible to obtain the following effects.

(8) When leveling is performed on a horizontal surface by maintainingthe sensor substrate 10 in a horizontal state and coating the first UVcurable resin 32 on the horizontal surface of the sensor substrate 10,the base precursor 33 with a uniform thickness is formed using thesurface tension and the weight of the first UV curable resin 32. Thebase precursor 33 is solidified by emitting UV light thereto, so that itis possible to form the base 31 having a uniform thickness. At thistime, volume contraction occurs in the base 31, but in a previousprocess superimposing the sensor substrate 10 and the light blockingsubstrate 40, and thereby not influencing on the gap between the sensorsubstrate 10 and the light blocking substrate 40.

(9) Furthermore, the base 31 is configured to occupy 90% or more of thelight transmitting member 30, and the light transmitting resin 35 isconfigured to occupy less than 10% of the light transmitting member 30.Accordingly, the base 31 is thickly formed compared to in the embodiment1 and the base 31 is formed at a uniform thickness using theabove-mentioned method, and thereby it is possible to dispose the lightblocking substrate 40 and the sensor substrate 10 at a predetermined gap(approximately 100 μm) even without forming the sealing material 20which is in the embodiment 1. Accordingly, it is possible to provide theimaging device 2 at a lower cost than in the embodiment 1.

The light transmitting resin 35 may be formed not using thethermo-curable resin 36, but using a resin having properties of both UVcurability and thermo-curability. By coating the UV curability, it ispossible to rapidly cure the light transmitting resin 35.

A manufacturing method of the present embodiment may be applied to amanufacturing method of an electronic device having a pair of substratesformed at a predetermined interval the same as in the first embodiment,for example, a manufacturing method of attaching a touch panel on anelectro-optical apparatus such as a liquid crystal display device and amanufacturing method of attaching a dust-proof glass on theelectro-optical apparatus as a light bulb in the projector use.

The present invention is not limited to the above-mentioned embodiment,and it is possible to add various changes and modifications to theabove-mentioned embodiment. The modification example will be describedbelow.

Modification Example 1

In the imaging device 1 of the embodiment 1, the light transmittingresin 35 is filled between the base 31 and the light blocking film 42(refer to FIG. 2). In addition, the light transmitting resin 35 isformed by performing a heat treatment on the thermo-curable resin 36,and is a transparent solid.

In the imaging device of the present modification example, the lighttransmitting material filled between the base 31 and the light blockingfilm 42, that is, a material equivalent to the light transmitting resin35 in the embodiment 1 may be a transparent material having fluidity.

An example of the transparent material having fluidity which is filledbetween the base 31 and the light blocking film 42 are preferably, forexample, an organic metal compound such as metal alkoxide, metalcarboxylates, metal chelates, and the like. A specific example of theorganic metal compound is aluminum-based metal complexes (Futabaelectronic industry (Co.) make, Ole dry) and the like. Such metalcomplexes have hygroscopic property in addition to light-transmittingproperty, so that, for example, it is possible to exclude the influenceof water on the photodiode 13 disposed in the sensing region 5.

Other suitable examples of the transparent material having fluidity maybe high viscous liquid such as fluidity paraffin, silicone oil, andmodified silicone oil. In a case where air bubbles are present in thetransparent liquid, it is possible to inhibit the movement of the airbubbles having a high viscosity.

As described above, according to the imaging device related to thepresent embodiment, it is possible to obtain the following effects inaddition to the effects in the embodiment 1.

In the present embodiment, the light transmitting material filledbetween the base 31 and the light blocking film 42 does not have avolume change equivalent to the volume contraction during curing of thethermo-curable resin 36 in the embodiment 1, so that it is possible toform the gap between the light blocking substrate 40 and the sensorsubstrate 10 with higher accuracy.

Inspection Apparatus Outline of Inspection Apparatus

Next, an example of an inspection apparatus equipped with the imagingdevice of any one of the above-described embodiment 1, embodiment 2, andmodification example 1 will be described.

FIG. 9 is a schematic view illustrating a configuration of theinspection apparatus.

The inspection apparatus 100 is a biometric authentication device whichperforms personal authentication by capturing the vein image of a fingerF. As shown in FIG. 9, the inspection apparatus 100 includes a detectionunit 110, a memory unit 140, a control unit 150, an output unit 160, andthe like.

The detection unit 110 is an imaging device 1 according to theembodiment 1, and emits emitting light IL from a light emitting unit 120to the finger F to detect reflected light RL from the finger F. Inaddition to the imaging device 1 according to the embodiment 1, it ispossible to use any one of the imaging device 2 of the embodiment 2 andthe imaging device of the modification example 1.

The detection unit 110 includes the light-emitting unit 120(illumination substrate 50, refer to FIG. 1), the MLA substrate 60 (notillustrated), the light blocking substrate 40 (not illustrated), thelight sensing unit 130 (sensor substrate 10, refer to FIG. 1), and thelike. The emitting light IL is light in a near infrared region emittedfrom the light emitting unit 120, and the wavelength is, for example,750 to 3000 nm (more preferably 800 to 900 nm). The emitting light IL isscattered when reaching inside the finger F, so that a portion thereofis toward the light sensing unit 130 as the reflected light RL.

In the light sensing unit 130, the photodiode 13 detecting light in thenear infrared region is disposed. The reduced hemoglobin flowing veinshas a property of absorbing light in the near infrared region.Therefore, when the finger F is captured using the photodiode 13detecting the light in the near infrared region, a venous portion underthe skin of the finger F appears dark compared to the surroundingtissues. Patterns provided by a difference of the brightness are thevein image. The reflected light RL from the finger F is converted to anelectrical signal (light sensing signal) having a signal levelcorresponding to the amount of light by the light sensing unit 130.

The memory unit 140 is a non-volatile memory such as a flash memory, ahard disk, or the like. As a master vein image of the personalauthentication, the vein image of the finger F (for example, right indexfinger) which is registered in advance is memorized.

The control unit 150 includes a Central Processing Unit (CPU), a RandomAccess Memory (RAM), and the like, and controls ON and OFF of the lightemitting unit 120. In addition, the control unit 150 reads a lightsensing signal from the light sensing unit 130, and generates a veinimage of the finger F based on the read light sensing signal of oneframe portion (imaging region portion). Furthermore, the control unit150 combines the generated vein image with the master vein imageregistered in the memory unit 140 to perform the personalauthentication.

The output unit 160 is, for example, a display unit or a voicenotification unit, and notifies a authentication result by a display orvoice.

By the above-mentioned configuration, the inspection apparatus 100 maycapture the vein image of the finger F with a high accuracy to performthe personal authentication.

In addition, a part of the living subject which is an object of the veinauthentication may be a palm, the back of the hand, an eye, or the like.

The detection unit 110 described above may be applied to a smallbiosensor which may be always installed in a medical and health fields.Furthermore, as the inspection apparatus equipped with the detectionunit 110, in the medical and health fields, it is possible to provide,for example, pulse rate monitor, a pulse oximeter, blood glucose meter,or fruit sugar content meter. Furthermore, using the detection unit 110,it is possible to provide a personal computer or a mobile phone having abiometric authentication function.

In addition, the detection unit 110 may be applied to an image readingdevice like an image scanner, a copier, a facsimile, a bar code reader,and the like. In addition, in a case of coating the detection unit tothe image reading apparatus, it is preferable to use light in a visibleregion instead of light in the near infrared region as the emittinglight IL or the reflected light RL.

The entire disclosure of Japan Patent Application No. 2012-191445, filedAug. 31, 2012 is expressly incorporated by reference herein.

What is claimed is:
 1. A method of manufacturing an electronic devicehaving a pair of substrates disposed to be opposite to each other at apredetermined gap, the method comprising: forming a base on onesubstrate of the pair of substrates; coating the periphery of the basewith an adhesive including a gap material forming the predetermined gap;coating the surface of the base with a light transmitting resinmaterial; disposing the pair of substrates at a predetermined gap bybringing the other substrate of the pair of substrates in contact withthe light transmitting resin material to be superposed on the onesubstrate; and solidifying the adhesive.
 2. The method of manufacturingan electronic device according to claim 1, wherein a volume of thelight-transmitting resin material coated in the coating of thelight-transmitting resin material, when the pair of substrates aresuperposed each other at the predetermined gap, is smaller than thevolume of a space surrounded by the pair of substrates, the base, andthe adhesive.
 3. The method of manufacturing an electronic deviceaccording to claim 2, wherein the disposing of the pair of substrates atthe predetermined gap is performed using a depressurized atmosphere. 4.The method of manufacturing an electronic device according to claim 3,wherein the adhesive is a photo-curable resin, and thelight-transmitting resin material is thermo-curable resin.
 5. The methodof manufacturing an electronic device according to claim 4, wherein thepredetermined gap is 50 μm or more, wherein, in a total volume which isa sum of the volume of the base and the volume of the light-transmittingresin material which are disposed between the pair of substrates, thebase is formed so as to have a 50% or more volume occupancy.
 6. Themethod of manufacturing an electronic device according to claim 5,wherein the base is formed using photo-curable resin.